MPR03X

Sensors

2

Freescale Semiconductor

1

Device Overview

1.1

Introduction

MPR03X is a small outline, low profile, low voltage touch sensor controller in a 2 mm x 2 mm

μDFN which manages up to three

interrupt output advises the host of electrode status changes. The interrupt output is a multiplexed with the third electrode output,

so using the interrupt output reduces the number of electrode inputs to two. The MPR03X includes three levels of input signal

filtering to detect pad input condition changes due to touch without any processing by the application.

1.2

Internal Block Diagram

Figure 2. Functional Block Diagram

ELE0

ELE1

ELE2

0

1

2

012

Current SourceMultiplexor

Iref

3

Set Source Current

Mirror

Iset

Select Chan

Select

Chan

Set Input Channel

Sel

Set Grounded

Electrodes

10 Bit ADC

Enable

Convert

Clock

Data

10

ADC Result

8MHz

Start Conversion

Shutdown

2

4

Interrupt

Controller

I²C

Interface

32 kHz

Oscillator

User

Registers

Debounced

Results

Magnitude

Comparator

Average

Filtered

Debounce

Result

Debounce Filter Registers

4 x Max Registers

4 x SumRegisters

4xMin Registers

SDA

SCL

IRQ SET

CLR

Shutdown

Debounce

Interval

Debounce

Count

Sample

Interval

Sample

Count

Debounce

and

Sample

Counters

Average

Filtered

Sample

Result

Sample Filter Registers

Max Register

SumRegister

Min Register

Set Source Current

Set Input Channel

ADC Result

8MHz

Start Conversion

Shutdown

8MHz

Oscillator

Shutdown

ADC Controller

Traffic

SDA

SCL

IRQ

32 kHz8 MHz

Set Grounded

Electrodes

Number of

Electrodes

Un-Touched

Baseline

Filter

0V

REXT